HCFO-containing polyurethane foam-forming compositions, related foams and methods for their production
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Solution Overview
Problem
Rigid polyurethane foams with improved thermal conductivity are needed to reduce energy usage and cost, while maintaining favorable foam physical properties and processing characteristics, using less hydrochlorofluoroolefin (HCFO) as a blowing agent.
Innovation Solution
A polyurethane foam-forming composition comprising a polyol blend of aromatic amine-initiated polyether polyol, saccharide-initiated polyether polyol, and aromatic polyester polyol, combined with a blowing agent composition that includes a hydrochlorofluoroolefin and a carbon dioxide-generating chemical blowing agent, to achieve a reduced HCFO content while maintaining thermal insulation properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If fluorocarbons (CFCs, HFCs, HCFCs) are used as blowing agents, then thermal conductivity is low (good insulation), but they are greenhouse gases that have been phased out
Solution Approach 1:
The patent changes the chemical composition parameters of the blowing agent from traditional fluorocarbons to HCFO-based formulations. Specifically, it uses HCFO-1233zd(e) as the primary physical blowing agent combined with chemical blowing agents, achieving both environmental compliance and acceptable thermal insulation properties
Solution Approach 2:
The patent employs a composite blowing agent system combining physical blowing agents (HCFO-1233zd) with chemical blowing agents (water, organic carbonates, formate-blocked amines). This composite approach allows the foam to achieve desired cell structure and insulation properties while using environmentally acceptable materials
2Object-affected harmful factors
If HCFO is used as a blowing agent, then environmental friendliness is improved, but cost increases and thermal conductivity may worsen
Solution Approach 1:
The patent optimizes the HCFO content parameter within specific ranges (5-30 wt% of total composition, with 10-25 wt% being preferred) to balance thermal performance and environmental benefits. It also controls the OH number (300-500 mg KOH/g) and functionality (3.5-4.5) of polyether polyols to achieve optimal cell structure and insulation properties
Solution Approach 2:
The patent creates different local compositions within the foam system by using specific polyol blends (aromatic amine-initiated polyether polyol with 3.5-4.5 functionality, saccharide-initiated polyether polyol with 4-6 functionality, and aromatic polyester polyol with 1.5-3 functionality) that work synergistically with HCFO to achieve uniform cell structure and improved thermal insulation
3Quantity of substance
If HCFO usage is reduced, then cost decreases, but maintaining thermal insulation properties and foam physical properties becomes difficult
Solution Approach 1:
The patent merges multiple blowing mechanisms by combining physical blowing (HCFO expansion) with chemical blowing (CO2 generation from water/carbonates/amines). This combination allows reduced HCFO content (5-30 wt%) while maintaining adequate cell formation and insulation properties through the complementary action of both blowing systems
Solution Approach 2:
The patent adjusts critical parameters including isocyanate index (1.05-1.30), polyol blend composition (specific ratios of aromatic amine-initiated, saccharide-initiated, and aromatic polyester polyols), and blowing agent ratios to optimize foam structure and thermal performance at reduced HCFO levels
4Loss of energy
If polyol blend composition is optimized, then thermal insulation improves, but processing characteristics may be affected
Solution Approach 1:
The patent carefully balances polyol parameters (OH number: 300-500 mg KOH/g, functionality: 3.5-4.5 for aromatic amine-initiated polyol) and their ratios in the blend to achieve both improved thermal insulation and acceptable processing characteristics. The specific composition ranges are optimized to ensure proper foam rise, cell structure, and dimensional stability
Solution Approach 2:
The patent uses different polyol types with specific local properties (aromatic amine-initiated for cell structure, saccharide-initiated for foam rise, aromatic polyester for flexibility) in controlled proportions to achieve both thermal performance and processing ease in different regions of the foam system
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution produces polyurethane foams with improved thermal insulation properties and reduced HCFO usage, maintaining dimensional stability and processing characteristics, leading to potential energy and cost savings in applications such as refrigeration appliances.
Implementation Method 1
The physical blowing agent comprises a hydrochlorofluoroolefin
Implementation Method 2
a carbon dioxide-generating chemical blowing agent
Implementation Method 3
reacting a polyisocyanate and an isocyanate-reactive compound, usually a polyol
Implementation Method 4
The thermal insulating properties of closed-cell rigid foams are dependent upon a number of factors
Data Source
AI summary
Polyurethane foam-forming compositions, methods of producing polyurethane foams, polyurethane foams produced from such compositions made by such methods, as well as isocyanate-reactive compositions. The polyurethane foam-forming compositions include a polyol blend, a blowing agent composition, and a polyisocyanate. The polyol blend includes an aromatic amine-initiated polyether polyol, a saccharide-initiated polyether polyol, and an aromatic polyester polyol and has a content of —C2H4O— units of 3 to 6% by weight, based on the total weight of the polyurethane foam-forming composition. The blowing agent composition includes a hydrochlorofluoroolefin and a carbon dioxide-generating chemical blowing agent.